Grip strength tester



FIG. 1 is a perspective view showing the top and right side elevational view of the grip strength tester;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof the left side being a mirror image;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for grip strength tester, as shown and described. 